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Human Physiology
Week 1- Cell Biology
81
Physiology
Graduate
09/10/2013

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Cards

Term
What part of the cell is responsible for protein synthesis?
Definition
Ribosomes
Term
What part of the cell is responsible for protein synthesis and glycolysation?
Definition
Rough Endoplasmic Reticulum
Term
What part of the cell holds the nuclear envelope and DNA?
Definition
Nucleus
Term
What part of the cell is made up of actin microfilaments, microtubules, and intermediate filaments?
Definition
Cytoskeleton
Term
What part of the cell is considered the lipid (fats) bilayer?
Definition
Plasma membrane
Term
What part of the cell consists mostly of water and dissolved substances, organelles, and the cytoskeleton?
Definition
Cytoplasm
Term
What part of the cell is responsible for sorting, modifying, and packaging proteins, as well as apoptosis?
Definition
Golgi Apparatus
Term
What part of the cell digests proteins with acidic enzymes?
Definition

Lysosomes

 

"little stomach"

Term
What part of the cell is responsible for lipid and steroid synthesis, receptor attachment, enzyme storage & production, carbohydrate metabolism, Ca regulation, and gluconeogenesis?
Definition
Smooth Endoplasmic Reticulum
Term
What part of the cell is responsible for making ATP, fatty acid oxidation, cholesterol and steroid synthesis, decreasing apoptosis, and Ca regulation?
Definition
Mitochondria
Term
What part of the cell acts as an anchor for microtubules, especially during mitosis?
Definition
Centrosome with centrioles
Term

Which 3 types of lipids make up the lipid bilayer of the plasma membrane of the cell, and are proteins embedded within the lipids?

 

Definition

Phospholipids

Cholesterol

Glycolipids

 

Yes. 

Term

Are sugars (glucose), amino acids, nucleotides, proteins, and charges molecules (ions Na+, Cl-)

permeable or impermeable to the lipid bilayer?

Definition

Impermeable

 

(large and charged)

Term
What type of molecules are only SLIGHTLY permeable to the lipid bilayer of the cell?
Definition

Small and Polar molecules:

eg. urea, water, ethanol

Term

Are steroids such as O2, CO2, Nand fat soluble vitamins such as A, D, E, K 

freely, slightly, or impermeable to the lipid bilayer of the cell?

Definition
Freely permeable because they are small, uncharged, and /or non-polar.
Term
How do charged ions and larger molecules permeate the lipid bilayer?
Definition

Facilitation. 

They CANNOT simply diffuse. 

Term
What drives the movement of small, uncharged molecules across a cell membrane (lipid bilayer)?
Definition

Concentration gradient. 

 

Passively diffuse from high to low concentration, seeking equilibrium. 

Term
Are phospholipids polar, non polar, or both (amphipathic)?
Definition

Both. They are amphipathic. 

 

They have polar phosphate heads (slightly charged) so they can form hydrogen bonds with water, and are therefore hydrophilic. 

 

The fatty acid tails are uncharged and therefore non polar. They are attracted to other lipids and not water and are therefore hydrophobic. 

Term
Is a protein required for simple diffusion through a cell membrane?
Definition
No
Term
How does a substance that is too big or charged pass through a cell membrane?
Definition

Facilitated diffusion. 

A channel protein or carrier protein is required to enter the cell. 

Term
In facilitated diffusion, which proteins do not change shape, but may be gated to assist a substance entering the cell?
Definition

Channel Proteins

eg. ion channel

Term
Which proteins help facilitate diffusion into a cell by transporting molecules down the concentration gradient by binding and changing shape?
Definition

Carrier (or Transport) Proteins

eg. glucose transporter

Term

What is occurring when molecules flow from high to low concentration, or down electrochemical gradients? 

 

Is energy required?

Definition

Passive transport. 

 

No

Term

What is occurring when molecules are being pushed against their gradients?

 

Is energy required?

Definition

Active transport.

 

Yes. (Usually ATP)

Term
What is concentration gradient?
Definition

When substances move from high to low concentration in a cell.

Term
What is electrical gradient?
Definition
When charged substances are drawn to areas of opposite charge.
Term
What is the net gradient of a substance that depends on both concentration and charge?
Definition
Electrochemical gradient
Term
What type of transport requires chemical energy (eg hydrolysis of ATP) to move a substance against its gradient?
Definition
Primary Active Transport
Term
What type of transport uses the electrochemical gradient of one substance to transport a second substance against its gradient?
Definition
Secondary Active Transport
Term
Symport and Antiport are two types of what kind of transport?
Definition

Secondary Active Transport

 

Symport- 2 substances move in the SAME direction

 

Antiport- 2 substances move in OPPOSITE directions

 

NO energy required.

Term
What types of vesicular transport require ATP?
Definition

ALL.

Endocytosis, Exocytosis, Transcytosis

Term
Phagocytosis and Pinocytosis are what types of vesicular transport?
Definition

Endocytosis. 

 

When large substances enter the cell by pinching off part of the plasma membrane.

Term
What is it called when large substances (eg neurotransmitters) exit the cell via vesicles that fuse with the plasma membrane?
Definition
Exocytosis
Term
What is transcytosis?
Definition
When large substances cross the cell by entering one side and leaving the other side.
Term

What is the movement of a solvent (ie water) through a semipermeable membrane. 

(Water moves toward the area with more solute, or higher osmolarity)

Definition
Osmosis
Term

Does transciption or translation occur in the nucleus? In the ribosome?

What occurs?

Definition

Transcription occurs in the nucleus: DNA is transcribed into mRNA

Translation occurs in the ribosome: mRNA is translated into a protein

Term
What and where is chromatin?
Definition
It is a strand of nucleosomes with linker DNA between them. Is it loose and diffuse in a non-dividing cell, but folds tightly into chromosomes when the cell divides.
Term
What are nucleosomes?
Definition
DNA wrapped around 8 histone proteins
Term
What is the function of the nuclear pore and nuclear envelope?
Definition

m/t/rRNA exits the nucleus in a nuclear envelope through a nuclear pore.  

The nuclear envelope has a double lipid bilayer and is continuous with the RER.

Term
What is the part of DNA that codes for the ribosomes?
Definition
Nucleolus
Term
Describe the path of mRNA
Definition

mRNA leaves the nucleus and enters the cytoplasm; mRNA enters a ribosome.

Ribosomes translate mRNA into a protein by attaching a tRNA anticodon to an mRNA codon.

Amino acids then bind together and form a peptide chain: protein

Term
Where can you find ribosomes?
Definition

In the cytosol ("Free")

Attached to RER

In the mitochondria

Term
What is the function of Free ribosomes?
Definition

Free ribosomes make proteins that stay inside the cell

Term
What type of proteins cross the RER membrane only partially, and remain membrane bound?
Definition
Transmembrane proteins
Term
What type of proteins cross the RER completely and enter the lumen of the RER?
Definition
Secretory proteins
Term
After the RER, where do proteins move (via vesicles)?
Definition
Golgi Apparatus
Term
How does the golgi apparatus modify proteins?
Definition
By adding a sugar for glycoproteins
Term
What organelle sorts proteins into vesicles aimed for the same destination?
Definition
Golgi apparatus
Term
What are the possible places for a RER/Golgi protein to end up?
Definition

Membrane vesicle (attached to membrane)

Secretory vesicle (outside cell)

Transport vesicle (inside cell)

Term
Can a transmembrane protein ever separate to a vesicle, or can a secretory vesicle ever remain inside the cell?
Definition
Nope. They're coded to function only in these ways.
Term
What is the function of the Smooth ER?
Definition

Synthesize fatty acids & steroids

Detoxify lipid soluble substances (drugs, alcohol, pesticides)

Help release glucose into blood

Stores & releases Ca2+ in muscle cells

Term
Which organelle contains the cells digestive enzymes?
Definition
Lysosomes
Term
Which organelles degrade cytosolic proteins that are non-functional or misfolded into peptides?
Definition
Proteosomes
Term
Which organelles contain oxidases (enzymes that oxidize organic substances: fatty/amino acids; toxic substances) and are numerous in liver cells?
Definition
Peroxisomes
Term
What are the 3 components of the cell's cytoskeleton?
Definition

Actin Microfiliments

Intermediate filaments

Microtubules

Term
What is reponsible for cell shape and what are the components?
Definition

Actin Microfilaments:

made of actin and myosin proteins

Term
Which motor molecule moves Actin to enable cell movement?
Definition
Myosin
Term
Do actin microfilaments (actin & mysosin) require ATP to assemble?
Definition
Yes
Term
What organelle aligns and separates the chromosomes during mitosis?
Definition

Microtubules

Make up cilia and flagella

Term
Which two motor molecules make up microtubules and engage the separating (pulling apart) action?
Definition

Kinesin (+) end

Dyenin (-) end at the centriole

Term
Which organelle is responsible for a cells scaffolding and stability?
Definition
Intermediate filaments (ie. keratin)
Term
What substances enter the Krebs Cycle to produce energy?
Definition

Fatty Acids

Amino Acids

Sugars

Term
What is produced from the Krebs Cycle?
Definition
NADH
Term
In the Krebs Cycle, what is produced from NADH?
Definition
From NADH, electrons go to the Electron Transport Chain, and H+ ions power oxidative phosphorylation to make ATP
Term
Besides containing the Krebs Cycle and making ATP, what are the other functions of the Mitochondria?
Definition

Steroid synthesis

Triggers apoptosis (programmed cell death)

Term
What are the 3 stages of existence for a cell?
Definition

Alive and functional without dividing (G0)

The Cell Cyle: Grow & Divide (Interphase & Mitosis)

Apoptosis (Die)

Term
What are the phases of the Cell Cycle?
Definition

Interphase (G1, S, G2)

Mitosis (Nuclear division: Pro/Meta/Ana/Telophase; Cytokinesis)

Term
Is the cell dividing in Interphase?
Definition
No
Term
Is the cell replicating in Mitosis?
Definition
No
Term
During what phase of the Cell Cycle does DNA replicate?
Definition
S phase of Interphase
Term
What 2 components are dividing during the cell's mitotic phase?
Definition
Nucleus and Cytoplasm
Term
How many pairs of chromosomes do we have?
Definition

23.

22 + sex pair (xx/xy)

Term
Does meiosis create diploid or haploid daughter cells (or gametes)?
Definition
Haploid. (For reproduction: sperm or oocytes)
Term
Somatic cell division aka Mitosis produces diploid or haploid daughter cells?
Definition
Diploid. (for healing or growth)
Term
Which enzyme turns on cell division?  Which turns them off?
Definition

CDK's turn on G1, then continue in orderly progression through cell cycle. 

Cyclins turn CDK's on and off.

Term
What is the term for regulated, programmed cell death? Is inflammation produced?
Definition

Apoptosis.

No (cell destroyed from within).

Term

What is the term for pathological cell death?

What happens to the cell?

Definition

Necrosis.

The cell may swell, burst, spill contents and inflammation.

Term
What is the disease state characterized by uncontrolled, abnormal cell division?
Definition
Cancer
Term
What are the genes that code for proteins to stop cell division, or induce apoptosis?
Definition
Tumor suppressor genes (ie. BRCA)
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